In this Phase II project, Intelligent Optical Systems, Inc. (IOS) will prototype a cost-effective handheld chemical detection device that will enable first responders to rapidly and accurately identify multiple contaminants, measure their concentration, and define site boundaries. IOS's innovative multi-element optical sensor array (MOSA) device will incorporate a disposable optical chip bearing 14 chemically sensitive waveguides, and an optoelectronics and signal processing unit similar in size to a personal digital assistant. With waveguide widths on the order of 100 microns, the chip's high packing density will allow multiple chemical substances to be detected simultaneously with very low false alarm rates. Each waveguide channel will be fabricated of high-quality chemically permeable optical polymer containing a chemical indicator (sensor dye) designed to undergo a large and rapid optical change (e.g., optical absorbance shift, or fluorescence quenching) in the presence of a target analyte. The handheld unit will use an advanced system of semiconductor light sources and detectors to monitor changes in the light guided through the sensors. Although each waveguide channel will be designed to respond to a single substance or class of chemicals, false alarms resulting from cross response will be resolved by two distinctive approaches: First, the use of a secondary cladding that contains scrubbing agents against potential cross contaminants; second, sophisticated signal processing that combines the optical intensity at all wavelengths from all waveguide channels (28 signals) to unambiguously detect each analyte of interest. In the final product, disposable chips with different panels of indicator waveguides will be designed for different applications; this will allow the universal handheld MOSA instrument to be used in virtually any chemical detection application, from occupational toxin monitoring to chemical release first response. In addition to demonstrating a prototype MOSA reader, this Phase II project will show how an electronically controlled micro-dispenser can be used to produce multi-waveguide optical chips that are highly reproducible, reliable, and inexpensive. These chips will have a long shelf life when packaged, thus allowing them to be disposable and stored in quantity. MOSA readout units and sensor chips will be easily affordable by industry, compliance monitoring agencies, fire departments, and hazmat response teams. Detailed cost analysis for the final Phase II and Phase III prototype is provided in the commercialization plan.